This is a note to let you know that I've just added the patch titled Fix potential infoleak in older kernels to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: fix-potential-infoleak-in-older-kernels.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Tue Nov 8 11:17:00 CET 2016 Date: Tue, 08 Nov 2016 11:17:00 +0100 To: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> From: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Subject: Fix potential infoleak in older kernels From: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Not upstream as it is not needed there. So a patch something like this might be a safe way to fix the potential infoleak in older kernels. THIS IS UNTESTED. It's a very obvious patch, though, so if it compiles it probably works. It just initializes the output variable with 0 in the inline asm description, instead of doing it in the exception handler. It will generate slightly worse code (a few unnecessary ALU operations), but it doesn't have any interactions with the exception handler implementation. Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/include/asm/uaccess.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -332,7 +332,7 @@ do { \ #define __get_user_asm_u64(x, ptr, retval, errret) \ __get_user_asm(x, ptr, retval, "q", "", "=r", errret) #define __get_user_asm_ex_u64(x, ptr) \ - __get_user_asm_ex(x, ptr, "q", "", "=r") + __get_user_asm_ex(x, ptr, "q", "", "=&r") #endif #define __get_user_size(x, ptr, size, retval, errret) \ @@ -375,13 +375,13 @@ do { \ __chk_user_ptr(ptr); \ switch (size) { \ case 1: \ - __get_user_asm_ex(x, ptr, "b", "b", "=q"); \ + __get_user_asm_ex(x, ptr, "b", "b", "=&q"); \ break; \ case 2: \ - __get_user_asm_ex(x, ptr, "w", "w", "=r"); \ + __get_user_asm_ex(x, ptr, "w", "w", "=&r"); \ break; \ case 4: \ - __get_user_asm_ex(x, ptr, "l", "k", "=r"); \ + __get_user_asm_ex(x, ptr, "l", "k", "=&r"); \ break; \ case 8: \ __get_user_asm_ex_u64(x, ptr); \ @@ -395,7 +395,7 @@ do { \ asm volatile("1: mov"itype" %1,%"rtype"0\n" \ "2:\n" \ _ASM_EXTABLE_EX(1b, 2b) \ - : ltype(x) : "m" (__m(addr))) + : ltype(x) : "m" (__m(addr)), "0" (0)) #define __put_user_nocheck(x, ptr, size) \ ({ \ Patches currently in stable-queue which might be from gregkh@xxxxxxxxxxxxxxxxxxx are queue-4.4/ubifs-abort-readdir-upon-error.patch queue-4.4/xhci-add-restart-quirk-for-intel-wildcatpoint-pch.patch queue-4.4/alsa-hda-adding-a-new-group-of-pin-cfg-into-alc295-pin-quirk-table.patch queue-4.4/dm-free-io_barrier-after-blk_cleanup_queue-call.patch queue-4.4/tty-limit-terminal-size-to-4m-chars.patch queue-4.4/mm-list_lru.c-avoid-error-path-null-pointer-deref.patch queue-4.4/usb-gadget-function-u_ether-don-t-starve-tx-request-queue.patch queue-4.4/ubifs-fix-regression-in-ubifs_readdir.patch queue-4.4/alsa-hda-fix-headset-mic-detection-problem-for-two-dell-laptops.patch queue-4.4/btrfs-fix-races-on-root_log_ctx-lists.patch queue-4.4/usb-serial-cp210x-fix-tiocmget-error-handling.patch queue-4.4/alsa-hda-merge-rirb_pre_delay-into-ctx_workaround-caps.patch queue-4.4/i2c-imx-defer-probe-if-bus-recovery-gpios-are-not-ready.patch queue-4.4/drm-dp-mst-clear-port-pdt-when-tearing-down-the-i2c-adapter.patch queue-4.4/mm-memcontrol-do-not-recurse-in-direct-reclaim.patch queue-4.4/usb-increase-ohci-watchdog-delay-to-275-msec.patch queue-4.4/alsa-hda-allow-40-bit-dma-mask-for-nvidia-devices.patch queue-4.4/vt-clear-selection-before-resizing.patch queue-4.4/hv-do-not-lose-pending-heartbeat-vmbus-packets.patch queue-4.4/usb-serial-ftdi_sio-add-support-for-infineon-triboard-tc2x7.patch queue-4.4/i2c-core-fix-null-pointer-dereference-under-race-condition.patch queue-4.4/mei-txe-don-t-clean-an-unprocessed-interrupt-cause.patch queue-4.4/alsa-hda-raise-azx_dcaps_rirb_delay-handling-into-top-drivers.patch queue-4.4/xhci-use-default-usb_resume_timeout-when-resuming-ports.patch queue-4.4/i2c-xgene-avoid-dma_buffer-overrun.patch queue-4.4/android-binder-add-strong-ref-checks.patch queue-4.4/h8300-fix-syscall-restarting.patch queue-4.4/fix-potential-infoleak-in-older-kernels.patch queue-4.4/libxfs-clean-up-_calc_dquots_per_chunk.patch queue-4.4/keys-fix-short-sprintf-buffer-in-proc-keys-show-function.patch queue-4.4/android-binder-clear-binder-and-cookie-when-setting-handle-in-flat-binder-struct.patch queue-4.4/genwqe-fix-bad-page-access-during-abort-of-resource-allocation.patch queue-4.4/usb-serial-fix-potential-null-dereference-at-probe.patch queue-4.4/alsa-usb-audio-add-quirk-for-syntek-stk1160.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html